Nutrition is a vital component of a healthy lifestyle. Focusing on our nutrition is important for muscle recovery after workouts and fueling all other aspects of our physiology. So we know nutrition is important for a healthy body and lifestyle, but what about after an operation?

Focusing on our nutrition before and after surgery has been shown to enhance your recovery and decrease your chances of infection and rehospitalization. If you just had, or are about to have surgery, this article will give you nutrition guidelines to focus on during your recovery!

Why Focus on Nutrition

The surgery itself is a stressor to the body, and there are normal reactions our body has to surgery. Now after surgery, we need to rest and recuperate so that our bodies can heal and rehabilitation can begin so that we can come back better than ever before. You would think that our body is totally relaxed since we are mostly lying around or doing easy walking to recover. But contrary to this belief, our body is jumping into action to try and fast-track our recovery. Our liver and muscles initially react by dumping glucose into our blood. Then our bodies break down and mobilize muscle proteins to begin healing the surgical site and any alterations to the underlying structures that the surgical team performed. This is an important response because it is our body's way of jump-starting repair, but it comes at a cost.

The cost of mobilizing our muscle proteins is that we are breaking down the muscle that we have to make the necessary repairs to the tissues that were operated on. That, coupled with the necessary limitations in activity after surgery, can lead to significant muscle loss. In young, healthy adult men, the rates of muscle atrophy (weakening and shrinking) after surgery can be up to 5.5% only one week after surgery. In older individuals, the numbers are even greater. Most of the atrophy (80%) occurs during the necessary rest period when we shouldn’t be putting a lot of weight on the joints that were operated on, so we can’t work out these tissues to stave off muscle wasting. But by focusing on our nutrition, specifically our protein intake, we can mitigate muscle atrophy during this time.

After surgery, our normal routines get thrown way out of whack. The necessary bed rest and limitations in activity have us lying around the house, watching more tv, reading, and/or playing more video games. Despite this increase in free time, most people aren't focusing on a healthy diet at this time either. In fact, somewhere between 22% and 36% of people consume necessary amounts of macronutrients like protein in the time period before and after surgery. This may be partly due to some of the misconceptions surrounding post-surgical nutrition. When we are in that activity-limited state after surgery, our total calories need to go down, but our protein consumption often needs to go UP!

Remember from earlier in the article that our bodies will start to break down our muscle tissues to jump-start our healing processes. One of the best ways to mitigate this process is by increasing protein consumption after surgery. This lets our body know that we have enough proteins coming in so that it doesn’t need to take it from our muscles, and research supports this theory.

Consuming protein as soon as possible after surgery has been shown to decrease muscle losses in the leg in operations involving the knee and the opposite leg. This protein can come in many forms depending on how you feel after surgery. Oftentimes we will not have a huge appetite after surgery, so the earliest and best form of protein may be a protein shake. Something like a simple whey protein shake is an easy way to get in enough protein to mitigate losses of muscle tissue. I mention whey as a good source because it has a high concentration of essential amino acids, which are protein-building blocks our body cannot make on its own, so it has to get them from food sources. These essential amino acids, especially leucine, signal to our bodies that we don’t need to take as much protein from our muscles because we are getting them from our diet.

Immediately After Surgery

After we wake up from surgery, we should get a protein shake as soon as possible. Then later in the day, we need to support that with a full meal if possible. This full meal should consist of a few different components. One of the main components is, of course, going to be protein, preferably at least 25 grams of protein, to offset muscle losses. But we also need to support this with other essential nutrients best found in good whole food sources. If you have a favourite healthy meal, this is the time. Usually, in the evening, after surgery, heavy meals don’t go down the easiest, so it may be best to stick with some things that are on the lighter side that you have eaten before and know work well with your stomach. If you still don’t quite have the stomach to eat a full meal with at least 25 grams of protein later in the day, then eating something is better than nothing, and you can always supplement it with another protein shake.

The Days After Surgery

In the few days to weeks after surgery, a couple of things have changed; our appetite should be back, and we should be eating full meals again. However, one thing that does not change is our protein requirement. During this time period, we will likely not be at full athletic activity; thus, our energy requirement is lower. Because our body uses and stores carbohydrates and fats as energy macronutrients, our intake should decrease. This is where a lot of people go wrong in their postoperative nutrition. We tend to increase our intake of junk food rich in carbohydrates and fats and forget about protein. But that is the opposite of what we should be doing because our bodies are still working around the clock to repair the surgical site so that we can function normally as soon as possible. So these next two paragraphs will focus on how much protein we should be ingesting and then how we should be ingesting that protein during the day.

The Weeks After Surgery

Our protein requirements will remain elevated in the weeks after surgery and during your recovery. However, our overall energy requirements will still be lower than when we are at full activity. Having more protein during your day will be beneficial because it will increase your satiety (i.e. decrease your hunger) while also decreasing the proportion of calories coming from foods our bodies use for energy, like carbs and fats. Thus we can keep the protein synthesis levels high while lowering the amount of energy macronutrients consumed. During this time, we should still aim for between 1.2 and 2.0 grams of protein per kilogram of body weight. However, another variable we should consider is the distribution or how we consume that protein throughout the day. This has a large effect on our protein synthesis rates.

Protein Distribution

What is the best protein distribution?

The best protein distribution for our goals is the one that produces the highest sustained levels of protein synthesis during the day. There are a couple of different options for us. We could; slowly spread that protein requirement in small doses 5-6x per day, Have a few large intakes, or have one very large intake late in the day. Each of these has pros and cons, but one intake strategy maximizes protein synthesis. The Best way to consume protein to maximize our protein synthesis is to consume the majority of this protein in larger doses spread out in 3-4 intakes during the day, starting early in the morning.

Why early in the morning?

We need to begin protein consumption in the early part of the day because if we are also making sure to get the necessary amount of sleep (7-9 hours on average) then we have basically just done a 7-9 hour fast. This 7-9 hour fast is enough time for your body to decrease muscle protein synthesis signals until the necessary amounts of protein are available for synthesis to ramp up again.

Researchers in the early 2000s wanted to directly test the difference between two different kinds of protein intake; moderate to high consumption throughout the day or one large intake at the end of the day. To do this, they split subjects into two groups; one group ingested 90 grams of protein during the day, and their distribution was even throughout the day, so 30 grams for breakfast, 30 grams for lunch, and 30g for dinner. The second group also took in 30 grams of protein during the day; the only difference was the distribution of this consumption throughout the day. This group took in 10g of protein in the morning, 15g with lunch, and 65g of protein with dinner.

These differences in protein distribution had a large effect on protein synthesis rates. Group 1 (even distribution) had protein synthesis rates that were 25% higher than the rates in group 2 (Mamerow et al., 2014). One of the major reasons for this is likely that the participants in group 1 initiated their protein synthesis earlier in the morning with their 30g of protein intake versus the 10g from group 2.

How much protein do I need in a meal?

Remember that in the study mentioned above, the second group with the 10 grams of protein consumed in the morning did not have the same initiation of protein synthesis like the first group.

This is likely because the 10 grams of protein did not reach what is referred to as the “meal threshold” (Layman et al., 2015) to initiate protein synthesis. In other words, our body needs more than 10g of high-quality protein to start the process of muscle protein synthesis.

The specific meal requirement is more difficult to decipher but likely depends on the amount of a specific amino acid we intake; leucine. Leucine is a key amino acid initiating the cascade of metabolic events leading to muscle protein synthesis. This role of leucine has been well established (Norton et. al., 2012) (Layman, 2002)(Jackman et al., 2017), and the level of necessary leucine is supposedly somewhere over 2.0-2.2 grams.

This may lead to us thinking that we must go out and get a bunch of leucine supplements. The amino acid leucine is subcategorized under the structural category of being a branched-chain amino acid (BCAA). These findings are one of the reasons that BCAA supplementation has had a lot of hype in recent years.

However, it is important to remember that leucine is just an amino acid. Which is what our bodies break proteins into when we digest them anyways. Leucine accounts for over 8% of amino acids found in proteins, especially when these protein sources are derived from animal sources like meat, eggs, chicken and fish. So we typically can achieve the necessary amounts of leucine and other BCAAs as long as we intake over 20 grams of protein in a meal.

So far, there have not been many studies that indicate a higher benefit to ingesting more BCAAs or protein on top of these recommendations (1.2-2.0g/kg/day). The majority of the studies that show the benefits of BCAA supplementation are in populations that are not ingesting enough overall protein or have difficulty consuming enough protein during the day. So an instance in which BCAA supplementation may be beneficial is immediately after surgery if you have lingering low appetite, nausea or other reasons that you are unable to meet your protein requirement.

What Not to Eat

After surgery, your body is in a high-inflammatory state. The foods that we eat should not add to this inflammation!

Limiting simple sugars and simple carbohydrates should be a priority.

Although you may need some comfort food, limit baking, white bread, sweets and candies.

FAQ:

Will eating this much protein make me gain weight?

Likely not, as long as we are in an overall calorie deficit or neutral. Protein is a macromolecule that is not very easily used by our bodies for energy. Researchers have compared the effects of diets that are a higher proportion protein vs carbohydrates in individuals trying to lose weight. They standardized the amount of calories each group was ingesting each day and other factors such as age and activity. They found that individuals in the higher protein diet had slightly higher rates of weight loss after ten weeks, lower losses of lean mass (so a higher proportion of fat tissue was lost), and they had higher levels of satiety (less hunger sensation) throughout the day (Layman, 2004)

What are the best foods after surgery?

The best foods after surgery are ones that are high enough in protein to meet our protein needs, as well as give us the other micronutrients and macronutrients to maximize our recovery. So our number one priority will still be to consume the right amount of protein in the best distribution for protein synthesis. Our second priority will be to consume other nutrient-rich foods such as fruits and vegetables to take the correct amounts of vitamins and minerals for our physiology. The best option is to focus on the least processed forms of these foods possible, so intaking our vitamin C from apples and oranges is going to be more beneficial to us than taking a vitamin C pill. When it comes to sources of protein, sources that are less processed and high in the amino acid leucine will ensure that we are consuming the right amounts of protein to optimize our muscle protein synthesis.

Below are some amounts of protein in common foods:

4 oz of steak: 23g
1 medium chicken breast: 37g
1 egg: 8g
Tofu 8.5oz: 29g
1 cup pinto beans: 12g

Source: https://cronometer.com/

Can these recommendations work on a vegetarian diet?

Yes! We understand that there are many reasons why one would be vegetarian and/or vegan; this does not mean that you cannot have a great recovery with nutrition to support that. However, when we look at the amino acid concentration of vegetarian sources of proteins, they have a lower concentration of the essential amino acids responsible for muscle protein synthesis. Thus you have to remain at the higher end of the protein intake range, so around 1.5-2.0 grams per kg of body weight per day.

This can be a challenge considering that vegetarian protein sources are already typically lower in protein. Supplementation with vegetarian protein drinks and shakes can be helpful to get in the required amount of protein in a day.

*Disclaimer:

This nutritional advice is meant to supplement your operating physician's advice, NOT replace it. Your operating physician and their team will know the nuances of your physiology and your specific surgery. This information is not meant to counteract or go against any dietary instructions or other information that your physician or their team has provided for you. Reach out to your physician's team if you have any questions or concerns regarding implementing these guidelines. This information is largely geared towards individuals receiving elective orthopedic surgeries and is not designed for nor meant for individuals undergoing or who have undergone surgical interventions to the gastrointestinal system, genitourinary system, or cardiorespiratory system. Ask your provider if this information is safe for you to utilize before doing so.

This document is catered towards individuals that are ages approximately 20-65. The information in this document can be helpful to individuals outside of this age range, but there are nuances to recommendations that affect these populations. For instance, teenagers (ages 13-20) do not display the same levels of anabolic resistance to muscle protein synthesis because their growth is more hormonally driven and not meal driven. So the meal threshold of 20-25g likely applies less or does not apply to these individuals.

References:

Hirsch, Katie R., Robert R. Wolfe, and Arny A. Ferrando. 2021. “Pre- and Post-Surgical Nutrition for Preservation of Muscle Mass, Strength, and Functionality Following Orthopedic Surgery.” Nutrients 13 (5). https://doi.org/10.3390/nu13051675.

Layman, Donald K. 2004. “Protein Quantity and Quality at Levels above the RDA Improves Adult Weight Loss.” Journal of the American College of Nutrition 23 (6 Suppl): 631S – 636S.

Mamerow, Madonna M., Joni A. Mettler, Kirk L. English, Shanon L. Casperson, Emily Arentson-Lantz, Melinda Sheffield-Moore, Donald K. Layman, and Douglas Paddon-Jones. 2014. “Dietary Protein Distribution Positively Influences 24-H Muscle Protein Synthesis in Healthy Adults.” The Journal of Nutrition 144 (6): 876–80.

Layman, Donald K., Tracy G. Anthony, Blake B. Rasmussen, Sean H. Adams, Christopher J. Lynch, Grant D. Brinkworth, and Teresa A. Davis. 2015. “Defining Meal Requirements for Protein to Optimize Metabolic Roles of Amino Acids.” The American Journal of Clinical Nutrition 101 (6): 1330S – 1338S.

Norton, Layne E., Gabriel J. Wilson, Donald K. Layman, Christopher J. Moulton, and Peter J. Garlick. 2012. “Leucine Content of Dietary Proteins Is a Determinant of Postprandial Skeletal Muscle Protein Synthesis in Adult Rats.” Nutrition & Metabolism 9 (1): 67.

Layman, Donald K. 2002. “Role of Leucine in Protein Metabolism during Exercise and Recovery.” Canadian Journal of Applied Physiology = Revue Canadienne de Physiologie Appliquée 27 (6): 646–63.